The Sixth-Generation fighter plane commonly known as the Tempest has taken a major step toward being reality after Britain, Japan, and Italy signed an international treaty in Tokyo to create a formal partnership to develop a new supersonic aircraft.
Japan s 1947 constitution rejects the militarism that led the empire to disaster in the Second World war. But in recent years, the Tokyo government has sought to relax the prohibition on closer military co-operation with the West.